TLI, DT, AT))
return ReplaceInstUsesWith(I, V);
+ // fsub nsz 0, X ==> fsub nsz -0.0, X
+ if (I.getFastMathFlags().noSignedZeros() && match(Op0, m_Zero())) {
+ // Subtraction from -0.0 is the canonical form of fneg.
+ Instruction *NewI = BinaryOperator::CreateFNeg(Op1);
+ NewI->copyFastMathFlags(&I);
+ return NewI;
+ }
+
if (isa<Constant>(Op0))
if (SelectInst *SI = dyn_cast<SelectInst>(Op1))
if (Instruction *NV = FoldOpIntoSelect(I, SI))